xkcd.WTF!?

Explanation ➲

"If all your friends jumped off a bridge, would you jump too?" This is a common question, used to challenge a decision based on the bandwagon effect. It challenges someone to consider whether something is really a good idea, even if everyone else does it (in this case, friends). The sentence is, upon closer analysis, a straw man attack that over-extrapolates the bandwagon effect.

Cueball responds by assuming that if all of his friends jumped off a bridge, there must have been some extreme circumstance that made it logical to do so; for example, that the bridge is on fire. This points out a logical fallacy with the question: if a large group of people all decide to jump off a bridge, there's probably a good reason for them to do so. This is especially true, since the question specifically references "all your friends", which means that these are people who he knows, and are mostly "level-headed and afraid of heights", which makes it unlikely that they're all acting in a random and dangerous way, and much more likely that they're driven by a good reason. A better bandwagon example would be "If all your friends are getting a new phone, would you buy one too?"

The title text suggests that, even if there is nothing wrong with the bridge, the person asking the question is not acting right. The proper reaction to any group of people jumping off a bridge would be concern about the people involved, particularly if all of the people involved are your friends. If the jump is truly dangerous, he should be concerned for their physical safety, and if the action was truly not justified by the circumstances, then he should be concerned about their mental and emotional state. The implication that he should just dismiss their actions and avoid them seems deeply callous.